Basic or Bedazzled?

I’m so Fancy ….

Silver Fox Shaving Soap is elegant in it’s simplicity.  It contains only that which is necessary to make soap, with a nod towards earthly pleasures via the fragrance.  But that’s it.  It is an open wheeled car in a world of coupes.  Can we take it to the next level and make it look fancy?  We can.  Can we improve it even more?  Maybe.  In this article I will explore color and consistency, along with a discussion of performance vs aesthetics.

The Players

There are three new components I will be using in this batch:

  • Sodium Lactate (SL) – This is the sodium salt of lactic acid.  This compound acts as a humectant/moisturizer in lotions.  In soaps, it is said to change the consistency of batter or hot soaps, as well as harden the cooled/cured soap.
  • Tetrasodium EDTA (EDTA) – Ethylenediaminetetraacetic acid.  How’s that for a mouthful?  Ethylenediaminetetraacetic acidis a chelating agent; it binds metal ions and removes them from suspension.
  • Titanium Dioxide (TiO2) also called Ti or Titanium White – This is a naturally occurring metal oxide used to opacify (make less transparent) colored products , or to create a white tint in products.

Sodium Lactate

Sodium Lactate can be purchased from many soap and cosmetic-related vendors.  It is available as a white powder, but is most commonly purchased as a slightly viscous pale yellow liquid.  If one researches usage rates in various books, articles, and websites, ranges from 0.5% to 4% are given.  Many recipes out there call for a teaspoon per pound of oil (PPO.)   I abhor that sort of measurement.  Sure it’s easy for the kitchen soap queen to do, but it tells us nothing quantitative.  “Teaspoon” as described on the Interwebz could be that spoon in your drawer, or an incredibly accurate measure of 4.92892 ml/tsp.  According to the U.S. Library of Medicine 1 tsp is 5 ml.  Sodium Lactate’s density is 1.33 g/ml as a powered.  Generally the syrup is a 60% concentration in water so that liquid we use would be 1.198 g/ml.  If you take that teaspoon (5 ml) and multiply that by the mass (1.198 g/ml) you end up with 5.99 g per tsp.  A pound is 454 g so 5.99 g per 454 g is 1.3%; that’s the empirical usage rate of 1 tsp PPO converted into real numbers.  Max usage in that incredibly inaccurate system of something PPO is  is about 3.6 tsp / PPO.

I rather arbitrarily chose an amount that ended up being 3.9% of the oil weight.   This amount was added to the lye water.  It was still quite warm, let’s color it 130°F when I added the SL.  For fun, my 3.9% is  3.5 tsp / PPO.


The soap was much easier to mix in the pot, going from the mashed potatoes of a hot processed batch to more of a Cream of Wheat consistency.  It was definitely easier to deal with, easier to stir, easier to keep in the pot, and much easier to mix in the oils and fragrance at the end.  When it came time to portion this into my tins, it was vanilla pudding consistency and was more of a blop and shake endeavor than the smear process I used with the non SL soap.   Very technical terms we are using here.   Just imagine trying to make a nice smooth top out of potatoes, versus pudding.

When the soap cooled it was much harder than normal, my fingernail test tells me it is every bit as hard as a bar of Ivory Soap for instance.  This would make pucks of soap created with 100% Potassium Hydroxide a very do-able thing.  A measure of “too much” SL in bar soap is when the soap crumbles when cut.  Since I am pouring this into tins I won’t be cutting it.

Since this ended up being on the high end of SL usage I decided to dial it back some to about 3%.  While the hardness was there when done the soap was back to what I’ll call soft mashed potatoes.  Better than none but a lot worse to work with than the 3.9% so barring any negative use testing, 3.9% will be my number.

I also have my suspicions about the use of sodium salts in shaving soap.  When someone gives me a sample of their shaving soap made in part with Sodium Hydroxide (to create a harder puck,) I very often feel a slight sensation of dragging/grittiness.   I can’t describe it better than that except to say it’s not as slick as snot (which is a good thing in this analogy.)  Since soap is a salt created from a fatty acid, and Sodium Lactate is another salt so created, will use of Sodium Lactate create this characteristic?  It’s an interesting thought experiment.  If it is sodium salts which create this effect, then use of very low percentages may allow the beneficial effect of the addition without realizing any of the detrimental impact.

Tetrasodium EDTA

This mouthful of an ingredient is used to help combat minerals in the water.   Calcium or Magnesium in the water will combine with the sodium or potassium ion preferentially and cause difficulty with lathering in extreme cases.  In nearly all cases there will be some soap scum generated which is the calcium or magnesium salt of your oils.  EDTA binds these minerals in a process known as chelation, which removes them from being able to react and cause these negative effects.  EDTA is available as Trisodium EDTA or Tertasodium EDTA.  The former is for neutral or acidic compounds, the latter is for alkaline.   Our soap is alkaline so we will use the Tetra-variety.

I calculated the EDTA addition at 0.5% of the total batch weight, which seems to be a common number for soapers.  It can be used up to 4% to combat the effects of hard water.

In closing on this chemical, it is deemed safe and anyone who tells you otherwise is a scare-monger.  Check the government testing here:

Final report on the safety assessment of EDTA, calcium disodium EDTA, diammonium EDTA, dipotassium EDTA, disodium EDTA, TEA-EDTA, tetrasodium EDTA, tripotassium EDTA, trisodium EDTA, HEDTA, and trisodium HEDTA.

In a nutshell:

“Based on the available data, the Cosmetic Ingredient Review Expert Panel found that these ingredients are safe as used in cosmetic formulations.”

Titanium Dioxide

Titanium Dioxide is an opacifier and a white coloring agent.  Used with other colors it can help make them pop.  Used alone it can make the soap less translucent and creamier looking.   It is non-reactive so unless you have to worry about how it plays with other colors (and we do not) there’s really no reason to worry too much about how much is used.  A typical addition for non-colored soap to help it look white is ~1%.  In this batch I calculated it at 0.5% of the weight of the oils.

Incidentally, this is the same pigment used in nearly anything that needs to be opacified or made white including foods, cosmetics, paints, even sunscreen.  Remember the white noses on the lifeguards?  Titanium dioxide at work.

The Results

Here’s a picture of this batch in the tin, versus the “classic” recipe cut into pucks.  You can really tell a difference.  The classic recipe was almost like vaseline in appearance, where the soap with SL and Ti are much creamier looking.

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On the Sodium Lactate, so far I have not detected any difference in the lather qualities between soap with and without SL.  I did notice though that the soap loads a little bit slower, likely due to the hardness of the soap.  I’ll keep testing and report back if I find any changes.  In a worst-case scenario, I can create potassium lactate by reacting KOH with Lactic Acid.


This soap is for me and I will be using these three additions to my soaps from now on.   You need to make up your own mind on it for your soaps.  Hopefully I have included enough information to help you make your decision.